Abstract: The invention provides for encoding position information for zone number, subtrack number and sector number, with less number of bits. The invention also provides for redundant position information to accurately determine the position of the transducer head.

Abstract: A method for adaptively controlling the write inhibit signal in a disk drive apparatus. The disk drive apparatus include magnetic disks manipulated such that the total space that is to be allocated for storing data has been measured and recorded such that the tracks for storing data have been servo written at a wider spacing than a nominal track spacing. The drive's operational circuitry includes access to modified write inhibit threshold data that is based on the drive's nominal design track misregistration allowance, plus any track width increase gained by adaptively controlling the track pitch. The modified write inhibit threshold essentially facilitates an acceptable delay in activating a write inhibit signal. The data tracks on each of the magnetic disks have been servo written utilizing the wider track spacing while maintaining the track misregistration allowance that corresponds to the nominal track spacing.

Abstract: A method for pattern-etching thick alumina layers in the manufacture of thin film heads (TFH) by using compatible metallic mask layers and a wet chemical etchant. The deep alumina etching facilitates a studless TFH device where the coil and bonding pads are deposited and patterned simultaneously, and vias are later etched through the alumina overcoat layer to expose the bonding pads. The method also enables the etching of scribe-line grooves of street and alleys across the wafer for sawing and machining of sliders. These grooves eliminate most alumina chipping due to stress and damage introduced by the sawing and machining operations. Similarly, pattern-etching of the alumina undercoat facilitates the formation of precise craters for recessed structures. These can improve planarity and alleviate problems related to adverse topography and elevated features of TFH devices.

Abstract: A disc drive has a head disc assembly and a printed circuit board. The head disc assembly has a first connector block with a plurality of first conductors, transmitting signals to and from the head disc assembly. The printed circuit board has a plurality of first electrical pads and a first cutout, the printed circuit board connected to the head disc assembly. A first flexible connection means electrically connects the first conductors of the first connector block of the head disc assembly to the first electrical pads of the printed circuit board, with the first cutout providing wiggle space and permitting accessing, positioning and mating of the first flexible connection means with the first connector block. In a specific embodiment, the first flexible connection means includes a third connector block and a first alignment means.

Abstract: A disc mounting system for mounting the discs of a disc drive in a fixed radial relationship to the hub of a spindle motor. The disc mounting system includes curved spring elements, having a substantially C-shaped axial cross section, which are curved on a radius greater than the radius of the central opening of the discs. One or more spring elements are utilized with each disc, and assembly tooling is used to bend the spring elements so that the discs, with the opening of the C-shaped springs engaging the inner diameter of the discs, can fit over the hub of the spindle motor. The assembly tooling is then removed to allow the spring elements to partially straighten, firmly engaging the discs relative to the spindle motor hub in the radial direction. In a first embodiment of the invention, alternative mechanisms are disclosed for establishing the axial positions of the discs.

Abstract: A mounting system attaches head suspensions to actuator head mounting arms of a disc drive actuator. The mounting system includes head suspension mounting plates and features on both the head suspension mounting plates and on the actuator head mounting arms that facilitate snap-fitting or press-fitting of the mating components, as well as features that ensure both accurate alignment and maintenance of the position of the mounted head suspensions in and about the major orthogonal axes.

Abstract: A passive actuator latching system in which a magnetic latch mechanism is mounted on an air damping mechanism. The air damping mechanism is optimized to the moving mass of the actuator and the specified mechanical shock tolerance to allow a relatively weak magnetic latch to resist unlatching due to relatively large short-duration mechanical shocks by providing damped compliance to the latching system during the application of mechanical shocks, and attenuating the shock force experienced at the magnetic interface. Various mechanisms for selecting the direction and magnitude of the damping of the compliance are disclosed.

Abstract: An improved attachment of an actuator E-block of an actuator assembly to a pivot bearing assembly for a disc drive, the E-block having a central bore having a pair of alignment edges to pressingly engage a cartridge bearing of the pivot shaft bearing assembly, and the cartridge bearing supporting a canted coil spring within a peripheral groove so that the spring is interposed between the cartridge bearing and the E-block within the E-block bore. One or more fasteners extend through the wall of the E-block adjacent the alignment edges to pressingly engage the cartridge bearing against the alignment edges, the canted coil spring filling the clearance gap between the cartridge bearing and the E-block bore to provide a resilient support to the E-block.

Abstract: A disc clamping system which exhibits a dual spring rate. The first spring rate is relatively low, allowing the disc clamping system to compensate for variations in dimensional tolerance buildup in the components of the disc stack, and is exhibited by the disc clamping system during initial tightening of the screws used to mount the disc clamp. The second spring rate is relatively high to provide tolerance to mechanical shocks applied in the disc drive's Z-axis, and is exhibited by the disc clamping system when the screws mounting the disc clamp to the spindle motor hub are tightened to a point of contact between contact features on the disc clamp and spindle motor hub.

Abstract: A method and apparatus for detecting and measuring head-disc interference, in a disc drive, for the purpose of taking preventative and corrective measures, to prevent disastrous head crashes and permanent data loss, is disclosed. The method and apparatus detect and measure the frequency modulation (FM) of a read back signal generated by longitudinal head oscillation, as a result of head-disc interference. The longitudinal head oscillation can be ascribed to the non-linear response of the air bearing supporting the head on the disk surface. The response exhibits a vibration frequency in the head in the 100 to 250 kHz range. The more severe the interference contact is, the higher the vibration amplitude which then leads to read signal frequency modulation (FM). A method and apparatus is described to detect the FM modulation and thereby to detect the severity of the head disk interference for proximity recording. A pre-written pattern on the disk can be read back to monitor for FM, and a modulation index, .beta.

Abstract: An electrical circuit package including disk drive operation and control circuitry is formed in multiple layers, including a compliant circuitry layer coextensive with the package, and additional conductive and dielectric layers to form relatively stiff circuit panels bonded to the compliant layer and spaced apart from one another. Portions of the compliant layer, between confronting edges of adjacent circuit panels, provide compliant joinder segments. Each joinder segment electrically couples its associated pair of circuit panels, and structurally couples the panels in a manner that permits a selective, non-coplanar orientation of the panels relative to each other. Thus, the panels are electrically and structurally coupled in a manner that facilitates testing the circuit package as a single unit, followed by installation of the package to a disk drive housing with the circuit panels integral with the housing and in the desired non-coplanar arrangement.

Abstract: A ramp loading and unloading system for the heads in a disc drive including an integrated latching mechanism for the disc drive actuator. The flexures that support the heads include ramp contact features which engage the ramps, and at least one of the ramp contact features includes a vertical latching face. At least one of the ramps includes a discontinuity forming a ramp latching face with which the vertical latching face of the ramp contact feature engages to latch the actuator. The ramp structure also includes a pivoting member which is rotated under influence of the actuator to allow the latching faces of the flexure and ramp structure to disengage.

Abstract: A disc mounting system for mounting the discs of a disc drive in a fixed radial relationship to the hub of a spindle motor. The disc mounting system includes one or more axially-extending tubular members inserted radially between the outer diameter of the spindle motor hub and the inner diameter of the discs. Various mechanisms for ensuring a tight radial connection between the spindle motor hub and the discs are disclosed.

Abstract: A magneto-optical head assembly that includes two load points. The two load points are laterally disposed from and longitudinally aligned with the center of the magneto-optical transducer carried on the head assembly. When contact between the head assembly and an asperity on the disc surface causes vibration of the head assembly in the pitch axis of the head assembly, the vibration is centered closely on the magneto-optical transducer, thus minimizing read/write signal modulation.

Abstract: A parking device for an actuator in a storage device which includes a voice coil motor having a magnet, providing a magnetic field including a magnetic flux, and a coil coupled to the actuator. The parking device includes a magnetically permeable capture structure forming a path for the magnetic flux and generating a capture region, the capture region being a region of magnetic flux adjacent to the capture structure; and a capture member, having a face plate, coupled to the actuator such that the capture member enters the capture region to park the actuator when the actuator is in a park position. In a further aspect, the parking device includes a magnet structure supporting the magnet, having a top plate and a bottom plate, wherein the capture structure is positioned between the top and bottom plates and forms a magnetic circuit path for the magnetic flux with the magnet, and the top and bottom plates.

Abstract: A data recording disk file includes rotatable disks with concentric data tracks thereon. The data disk file includes servo information recorded on at least one of the disks, at least one head for reading the servo information during rotation of the disk, and a voice coil motor (VCM) attached to the head for positioning the head relative to the data tracks. A servo is driven by signals read from the head to control the VCM. The servo includes a processor employing an estimator model for estimating the parameters of the VCM and for generating, from the estimated parameters and the servo information, a digital control signal. The digital control signal is converted to an analog control signal. The control signal is applied to a power amplifier which generates an input current for use by the VCM. The processor provides solely a single estimator model which operates in both saturated mode and linear mode depending on the magnitude of the digital PES.

Abstract: A spindle motor assembly adapted for rotationally supporting a load about a base includes a rotor rotatably mounted on the base with its outer periphery capable of supporting a load, a stator and a plurality of magnets mounted on the outer periphery of the rotor. The stator includes a plurality of stator laminations with selective portions of the stator laminations forming stator cores. A plurality of magnets are mounted on the outer periphery of the rotor in an operating relationship with the stator cores. A plurality of conductors are wound on the stator cores. The stator includes a resilient covering located around the plurality of laminations and further having a routing means to route the conductors between the stator cores, an attaching means to attach the stator to the base and a connecting means. The connecting means includes a first connector block with a plurality of first conductor pads, with a first end and a second end. Ends of the conductors are connected to the first end of the conductor pads.

Abstract: An apparatus and method for reducing adjacent track interference in a tape drive data storage system which employs a single read/write head controllably movable to any desired one of a plurality of parallel data tracks extending parallel with the length of the tape. The method consists of intentionally introducing azimuths of opposite direction for accesses to adjacent data tracks, with the magnitude of the introduced opposite azimuths being selected to exceed the azimuth range at which the head is capable of reliably reading data. In the apparatus of the invention the actuator used to move the head from track to track is mounted on a pivotable plate member, and the pivoting of the plate member is controlled by a stepper motor driven by control logic responsive to the access command being executed.

Abstract: A disc clamp assembly is provided for securing a plurality of information storage discs to a spindle hub on a disc drive spindle motor assembly. The disc clamp assembly includes a clamping ring and a resilient grip ring. The clamping ring has a raised Inner portion and rests on the information storage disc. The resilient grip ring has an inner diameter smaller than the diameter of the spindle hub, a middle portion to receive an axial force and a means for receiving radial force. The middle portion of the grip ring rests on the raised inner portion of the clamping ring. While the means for receiving radial force of the grip ring receives a radial force to radially expand the grip ring, the middle portion of the grip ring receives an axial force and applies the axial force to the clamping ring and the information storage discs. Upon removal of the radial force to the grip ring, the grip ring maintains the axial force applied to the information storage discs by gripping the spindle hub.